Method for manufacturing semiconductor package, substrate material for semiconductor package, and method for manufacturing substrate material for semiconductor package

Abstract

A method for manufacturing a semiconductor package, including cutting out a plurality of substrates having a first surface and a second surface from a substrate material for a semiconductor package having a first surface and a second surface on the back side of the first surface, classifying the plurality of cut-out substrates into a first substrate warped toward the first surface side when heated, and a second substrate warped toward the second surface side when heated, and mounting an electronic component including a semiconductor chip on a surface on the first surface side of a wiring substrate including the first substrate or on a surface on the second surface side of the wiring substrate including the second substrate.

Description

METHOD FOR MANUFACTURING SEMICONDUCTOR PACKAGE, SUBSTRATE MATERIAL FOR SEMICONDUCTOR PACKAGE, AND METHOD FOR MANUFACTURING SUBSTRATE MATERIAL FOR SEMICONDUCTOR PACKAGE

[0001] The present disclosure relates to a method for manufacturing a semiconductor package, a substrate material for a semiconductor package, and a method for manufacturing a substrate material for a semiconductor package.

[0002] In a semiconductor package, a semiconductor chip may be mounted on a wiring board having a core board formed from a substrate material and a multilayer wiring layer formed on the core board (see, for example, Patent Document 1).

[0003] JP 2017-11156 A

[0004] In the manufacture of semiconductor packages, when a semiconductor chip and a wiring board are connected through a heating process such as reflow, warping may occur due to differences in the thermal expansion coefficients of the semiconductor chip and the wiring board, etc. In order to properly connect the semiconductor package to a motherboard, it is desirable to suppress warping of the semiconductor package.

[0005] The present disclosure includes the following: [1] A method for manufacturing a semiconductor package, comprising: cutting out a plurality of substrates, each having a first surface and a second surface on the back side of the first surface, from a substrate material for a semiconductor package, the plurality of substrates having the first surface and the second surface; sorting the cut-out substrates into first substrates that warp toward the first surface when heated and second substrates that warp toward the second surface when heated; and mounting an electronic component, including a semiconductor chip, on the first surface of a wiring substrate including the first substrate, or on the second surface of a wiring substrate including the second substrate. [2] A method for manufacturing a semiconductor package, comprising: cutting out a plurality of substrates, each having the first surface and the second surface, from a substrate material for a semiconductor package, the plurality of substrates having the first surface and the second surface on the back side of the first surface; sorting the cut-out substrates into first substrates that warp toward the first surface when heated and second substrates that warp toward the second surface when heated; and mounting an electronic component, including a semiconductor chip, on the second surface of a wiring substrate including the first substrate, or on the first surface of a wiring substrate including the second substrate. [3] A substrate material for a semiconductor package having a first surface and a second surface on the reverse side thereof, wherein a plurality of sample substrates cut out from the substrate material for a semiconductor package, each having a rectangular shape of the first surface and the second surface measuring 60±1 mm in length and 60±1 mm in width, warp toward the first surface when heated. [4] The substrate material for a semiconductor package according to [3], wherein 90% or more of 10 or more sample substrates cut out from one sheet of the substrate material for a semiconductor package warp toward the first surface when heated. [5] The substrate material for a semiconductor package according to [3] or [4], wherein a plurality of the sample substrates exhibit a maximum warpage of 10 μm or more and 350 μm or less when heated to 260° C. [6] The substrate material for a semiconductor package according to any of [3] to [5], which has a label indicating the position of the first surface or the second surface of the substrate material for a semiconductor package.[7] The substrate material for a semiconductor package according to any one of [3] to [6], wherein the substrate material for a semiconductor package comprises an insulating substrate formed by heating and pressurizing a laminate including a plurality of prepregs containing an inorganic fiber base material and a thermosetting resin composition impregnated into the inorganic fiber base material. [8] The substrate material for a semiconductor package according to [7], wherein the laminate includes a combination of two or more types of prepregs containing different inorganic fiber base materials, and the two or more types of prepregs are stacked in a selected order so that a plurality of the sample substrates warp toward the first surface side when heated. [9] The substrate material for a semiconductor package according to [7] or [8], wherein the laminate includes a combination of two or more types of prepregs containing different thermosetting resin compositions, and the two or more types of prepregs are stacked in a selected order so that a plurality of the sample substrates warp toward the first surface side when heated.

[10] The substrate material for a semiconductor package according to any one of [7] to [9], wherein the insulating substrate is formed by heating and pressurizing the laminate under heating conditions in which the amount of heat applied to the laminate from one side of the laminate and the amount of heat applied to the laminate from the other side of the laminate are different, and the heating conditions are determined so that a plurality of the sample substrates warp toward the first side when heated.

[11] A container comprising: the substrate material for a semiconductor package according to any one of [3] to

[10] ; and a container that contains the substrate material for a semiconductor package and has a label indicating the position of the first side or the second side of the substrate material for a semiconductor package.

[12] A method for producing the substrate material for a semiconductor package according to [7], comprising forming an insulating substrate by heating and pressurizing a laminate including an inorganic fiber base material and a plurality of prepregs containing a thermosetting resin composition impregnated in the inorganic fiber base material.

[13] The method according to

[12] , wherein the laminate includes a combination of two or more types of prepregs containing different inorganic fiber base materials, and the two or more types of prepregs are laminated in an order selected so that the plurality of sample substrates warp toward the first surface side when heated.

[14] The method according to

[12] or

[13] , wherein the laminate comprises a combination of two or more types of prepregs containing different thermosetting resin compositions, and the two or more types of prepregs are laminated in an order selected to cause the plurality of sample substrates to warp toward the first surface side when heated.

[15] The method according to any of

[12] to

[14] , wherein the molded body is formed by heating and pressurizing the laminate under heating conditions in which the amount of heat applied to the laminate from one surface side of the laminate and the amount of heat applied to the laminate from the other surface side of the laminate are different, and the heating conditions are determined so that the plurality of sample substrates warp toward the first surface side when heated.

[0006] Even if the substrate warps when heated, warpage in the semiconductor package can be reduced.

[0007] FIG. 1 is a cross-sectional view showing an example of a substrate material. FIG. 2 is a schematic view showing a method for evaluating warpage of a substrate cut out from the substrate material. FIG. 3 is a schematic view showing a method for evaluating warpage of a substrate cut out from the substrate material. FIG. 4 is a schematic view showing a method for evaluating warpage of a substrate cut out from the substrate material. FIG. 5 is a cross-sectional view showing an example of a prepreg. FIG. 6 is a cross-sectional view showing an example of a method for manufacturing a substrate material. FIG. 7 is a cross-sectional view showing an example of a semiconductor package.

[0008] The present invention is not limited to the following examples: In this specification, the term "thickness direction" refers to a direction perpendicular to the two main faces of a sheet-like material that have the largest areas.

[0009] FIG. 1 is a cross-sectional view showing an example of a substrate material. The substrate material 100 shown in FIG. 1 is a sheet-like material having a first surface S1 and a second surface S2 on the reverse side thereof. The substrate material 100 is mainly composed of an insulating substrate 10 and metal foils 3 provided on both sides of the insulating substrate 10. The insulating substrate 10 includes an insulating resin layer 12A which is a cured thermosetting resin composition, and a plurality of inorganic fiber substrates 11 disposed within the insulating resin layer 12A. The plurality of inorganic fiber substrates 11 are stacked in the thickness direction of the insulating substrate 10.

[0010] Individual substrates cut out from the substrate material 100 are used to form wiring substrates for mounting semiconductor packages. For example, by using the metal foil 3 of the substrate material 100 or by forming wiring on the insulating substrate 10 after removing the metal foil 3, a wiring substrate for a semiconductor package having fine wiring can be manufactured. A substrate cut out from the substrate material 100 may be used as a core material for forming a wiring substrate for a semiconductor package.

[0011] The width of the substrate material 100 may be 200 to 2650 mm, and the thickness of the substrate material 100 may be 200 to 2000 μm.

[0012] The insulating resin layer 12A, which is a cured thermosetting resin composition, may have a dielectric constant of 3.0 or less, or 2.8 or less, at 10 GHz. The insulating resin layer 12A may have a dielectric loss tangent of 0.005 or less at 10 GHz. The dielectric constant can be measured using a test piece of the cured thermosetting resin composition, which is 60 mm long, 2 mm wide, and 300 μm thick. The test piece may be vacuum dried at 30°C for 6 hours before measurement. The dielectric loss tangent can be calculated from the resonant frequency and unloaded Q value obtained at 10 GHz. The measurement device may be a Keysight Technologies vector network analyzer E8364B, a Kanto Electronics Application Development CP531 (10 GHz resonator), and a CPMAV2 (program). The measurement temperature may be 25°C.

[0013] The insulating resin layer 12A, which is a cured thermosetting resin composition, may have a glass transition temperature of 120° C. or higher, or 140° C. or higher. The insulating resin layer 12A may have a glass transition temperature of 240° C. or lower, or 220° C. or lower.

[0014] A substrate having a first surface S1 and a second surface S2 that is cut out from the substrate material 100 may warp slightly toward the first surface S1 side or the second surface S2 side when heated. In the case of a substrate material that is manufactured without considering the direction of warping, multiple substrates cut out from a single sheet of substrate material will usually include both substrates that warp toward the first surface S1 side when heated and substrates that warp toward the second surface S2 side when heated, due to various factors based on variations in the material and process, etc. Therefore, it is generally difficult to predict toward which side an individual substrate will warp.

[0015] Therefore, the cut-out substrates may be classified into first substrates that warp toward the first surface S1 when heated and second substrates that warp toward the second surface S2 when heated. Electronic components, including semiconductor chips, may then be mounted on the surface of the wiring substrate determined based on the warpage direction of each substrate. When mounting electronic components, including semiconductor chips, on a wiring substrate including a substrate whose warpage direction is known in advance, warpage in the semiconductor package can be reduced by appropriately selecting the combination of the wiring substrate and the semiconductor chip so that the warpage directions cancel each other out. For example, the semiconductor chip and the substrate may be combined so that the warpage direction when heated is opposite. Electronic components may be selectively mounted on the surface of the wiring substrate including the first substrate on the first surface S1 side or the surface of the wiring substrate including the second substrate on the second surface S2 side. Alternatively, electronic components may be selectively mounted on the surface of the wiring substrate including the first substrate on the second surface S2 side or the surface of the wiring substrate including the second substrate on the first surface S1 side.

[0016] In order to classify the plurality of substrates into first substrates and second substrates, the warpage direction of each substrate can be evaluated by using each substrate as a sample substrate in a method for evaluating the warpage direction of a sample substrate, which will be described later.

[0017] Instead of classifying the cut-out substrates based on the warpage direction as described above, a substrate material may be prepared in which the warpage direction when heated is intentionally controlled. For example, a substrate material 100 may be prepared in which a plurality of sample substrates having a first surface S1 and a second surface S2, each rectangular and measuring 60±1 mm in length and 60±1 mm in width, are cut out from the substrate material 100 and warp toward the first surface S1 when heated. Here, of the two main surfaces of the substrate material 100, the surface on the side in which the plurality of sample substrates 20 warp can be considered to be the first surface S1 of the substrate material 100.

[0018] Figures 2, 3, 4, and 5 schematically show a method for evaluating the warpage direction of a sample substrate cut out from a substrate material. Figure 2 is a plan view of the substrate material, and Figure 3 is a plan view of a sample substrate (or substrate). A single substrate material 100 is cut out into multiple regions spaced apart by a predetermined distance D1 or D2 to form multiple sample substrates 20. The first surface S1 of each of the multiple sample substrates 20 has a rectangular shape with a vertical length L1 of 60±1 mm and a horizontal length L2 of 60±1 mm. The second surface S2 of each sample substrate 20 also has a rectangular shape similar to the first surface S1. The spacing D1, D2 between the regions cut out as the sample substrates 20 may be a minimum of 0.5 mm. The distance D3 between the region cut out as the sample substrate 20 and the edge surface 100E of the substrate material 100 may be a minimum of 20 mm. When the substrate material 100 has a metal foil 3, the warpage direction of the sample substrates with the metal foil 3 is typically evaluated.

[0019] 4 and 5 are schematic diagrams showing a sample substrate heated on a stage. The stage may be, for example, a glass plate. The sample substrate is heated by heaters provided below the stage and above the sample substrate. FIGS. 4 and 5 show cross sections along one of two diagonals of a rectangular first surface S1. FIG. 4 shows an example of a first substrate 21 that warps toward the first surface S1 when heated. FIG. 5 shows an example of a second substrate 22 that warps toward the second surface S2 when heated. The direction of warping of the sample substrate 20 due to heating is measured using a method including placing the sample substrate 20 on a horizontal surface of a stage 70 with the second surface S2 in contact with the stage 70, increasing the surface temperature of the sample substrate 20 from 30° C. to 260° C. and then decreasing it to 40° C., and measuring the relative height in the vertical direction Z at each position on the first surface S1 when the surface temperature of the sample substrate 20 has risen to 260° C. The surface temperature of the sample substrate 20 is measured using a thermocouple. The difference h between the height of the highest point and the height of the lowest point is determined for each of the two diagonals DL1 and DL2 on the first surface S1. For the diagonal with the larger difference h, the sample substrate 20 is determined to be a first substrate 21 when the center of the diagonal is higher than both ends of the diagonal, as illustrated in FIG. 4 . The sample substrate 20 is determined to be a second substrate 22 when the center of the diagonal is lower than both ends of the diagonal, as illustrated in FIG. 5 .

[0020] Most of the sample substrates 20 cut out from one sheet of substrate material 100 may be first substrates 21 that warp toward the first surface S1 side when heated. For example, 90% or more, 95% or more, or substantially all of 10 or more and 10 or less and 20 or less sample substrates 20 cut out from one sheet of substrate material 100 may be first substrates 21 that warp toward the first surface S1 side when heated.

[0021] Multiple sample substrates cut from a single substrate material 100 may exhibit a maximum warpage of 10 μm or more and 350 μm or less when heated to 260°C. The warpage amount can also be measured using the method for measuring the warpage direction described above. The warpage amount when the substrate material is heated to 260°C is the difference between the height of the highest point and the height of the lowest point across the entire first surface S1. The warpage amount exhibited by multiple sample substrates cut from a single substrate material 100 may be 10 μm or more, or 20 μm or more, or 300 μm or less, or 350 μm or less. 90% or more, 95% or more, or substantially all of 10 or more, or 10 to 20 sample substrates 20 cut from a single substrate material 100 may exhibit a warpage amount within the above range when heated. Normally, from the viewpoint of suppressing warpage of a semiconductor package, a substrate that does not substantially warp when heated is desired, but even in the case of a substrate that shows some degree of warpage, by appropriately selecting the combination with the semiconductor chip based on the direction of the warpage, it is possible to easily provide a semiconductor package with suppressed warpage.

[0022] A substrate material 100 from which a substrate warping toward the first surface S1 is cut out may have a label 110 indicating the position of the surface (first surface S1) from which the substrate cut out of the substrate material 100 will warp or the opposite surface (second surface S2), as shown in FIG. 2 . In the example of FIG. 2 , the label 110 is attached to the first surface S1 and includes a mark (WD) indicating that the surface to which the label is attached is the first surface S1 side. A substrate material from which a substrate warping toward the first surface S1 is cut out may be transported, stored, or used as a container containing a label indicating the position of the first surface S1 or the second surface S2. By referring to the label to confirm the position of the first surface S1 or the second surface S2, the substrate material can be used simply and accurately in the desired orientation.

[0023] A substrate material with a controlled warpage direction can be obtained, for example, by selecting a combination of multiple materials with different thermal expansion coefficients so that the thermal expansion coefficients change in the thickness direction of the substrate material. Normally, if the thermal expansion coefficient of the material forming the portion on the first surface S1 side is greater than the thermal expansion coefficient of the material forming the portion on the second surface S2 side, the substrate is likely to warp toward the first surface S1 side when heated.

[0024] FIG. 6 is a cross-sectional view showing an example of a prepreg used to manufacture a substrate material. FIG. 7 is a cross-sectional view showing an example of a method for manufacturing the substrate material 100 of FIG. 1 using a prepreg. The method shown in FIGS. 6 and 7 includes preparing a plurality of prepregs 1 including a sheet-like inorganic fiber substrate 11 and a thermosetting resin composition 12 impregnated into the inorganic fiber substrate 11, and forming an insulating substrate 10 by heating and pressurizing a laminate 5 including the plurality of prepregs 1. The laminate 5 shown in FIG. 7 further includes two metal foils 3 arranged to sandwich the stacked plurality of prepregs 1 from both sides. A molding process including increasing the temperature of the stacked laminate 5 while applying pressure to the laminate 5 forms an insulating substrate 10 formed by integrating two or more prepregs 1, and a substrate material 100 having metal foils 3 provided on both sides of the insulating substrate 10. An insulating resin layer may be provided between the metal foil 3 and the laminate 5. Heating the laminate 5 causes the thermosetting resin composition 12 to harden, forming the insulating resin layer 12 A of the substrate material 100 .

[0025] By combining two or more types of prepregs 1 that exhibit different thermal expansion coefficients after curing as the multiple prepregs 1 that make up the laminate 5, the linear expansion coefficient of the substrate material can be changed in its thickness direction. The thermal expansion coefficient of the prepreg 1 after curing can be adjusted, for example, by one or more selected from the type of inorganic fiber substrate 11, the components and their contents contained in the thermosetting resin composition 12, and the content of the thermosetting resin composition 12 in the prepreg 1. For example, the order in which the prepregs 1 are stacked may be selected so that the prepreg 1 that exhibits a relatively large thermal expansion coefficient after curing is arranged on the first surface S1 side, and the prepreg 1 that exhibits a relatively small thermal expansion coefficient after curing is arranged on the second surface S2 side.

[0026] The inorganic fiber substrate 11 can be, for example, a woven or nonwoven fabric containing inorganic fibers. The inorganic fibers constituting the inorganic fiber substrate 11 may be glass fibers, carbon fibers, or a combination thereof. The inorganic fiber substrate 11 may also be a glass cloth made of glass fibers. The proportion of glass fibers among the inorganic fibers constituting the inorganic fiber substrate may be 80 to 100 mass%, 90 to 100 mass%, 95 to 100 mass%, or 99 to 100 mass%. The glass fibers may be, for example, E-glass, S-glass, or quartz glass. The thickness of the inorganic fiber substrate 11 may be 0.01 to 0.20 μm. If the thermal expansion coefficient of the inorganic fibers constituting the inorganic fiber substrate 11 is large, the portion of the substrate material 100 corresponding to the cured prepreg 1 tends to exhibit a large thermal expansion coefficient.

[0027] The thermosetting resin composition 12 includes a thermosetting resin component. The thermal expansion coefficient after curing can be adjusted based on one or more of the type, content, and molecular weight of the components constituting the resin component. The thermosetting resin composition 12 may further include an inorganic filler. When the thermosetting resin composition 12 includes an inorganic filler, the portion of the thermosetting resin composition 12 excluding the inorganic filler may be considered as the resin component.

[0028] The thermosetting resin component is a component that forms a cured product upon heating and may include, for example, a thermosetting resin and a curing accelerator. The thermosetting resin is a compound that forms a crosslinked polymer upon heating and typically has a reactive functional group that undergoes a crosslinking reaction. The reactive functional group may be, for example, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, a vinyl group, a maleic anhydride group, or a combination thereof. The thermosetting resin may include an epoxy resin having two or more epoxy groups, an acrylate compound having two or more (meth)acryloyl groups, or a combination thereof. The content of the thermosetting resin may be, for example, 20 to 80% by mass based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler.

[0029] The thermosetting resin may include a thermosetting elastomer having a reactive functional group. Examples of thermosetting elastomers include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. The content of the thermosetting elastomer may be, for example, 10 to 70 mass % or 20 to 60 mass % based on the total mass of components other than the inorganic filler in the thermosetting resin composition.

[0030] Examples of the curing accelerator include peroxides, imidazole compounds, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. When the thermosetting resin is an epoxy resin, the curing accelerator may be, for example, an imidazole compound. The content of the curing accelerator may be, for example, 0.1 to 10% by mass, 0.5 to 5% by mass, or 0.75 to 3% by mass, based on the total mass of the components of the thermosetting resin composition other than the inorganic filler.

[0031] The thermosetting resin composition 12 may further include a thermoplastic resin as a resin component. The content of the thermoplastic resin may be, for example, 20 to 80 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler.

[0032] The thermoplastic resin may be, for example, at least one selected from an acrylic resin, a polyamide resin, a polyimide resin, and a polyurethane resin. The thermoplastic resin may have a siloxane group. For example, an acrylic resin, a polyamide resin, a polyimide resin, or a polyurethane resin may have a siloxane group. The resin having a siloxane group may be a silicone resin. The polyimide resin having a siloxane group may be, for example, a polymer produced by the reaction of a siloxane diamine with a tetracarboxylic dianhydride, or a polymer produced by the reaction of a siloxane diamine with a bismaleimide.

[0033] The thermoplastic resin may have one or more reactive functional groups at the molecular end or in the molecular chain, examples of which include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, a vinyl group, and a maleic anhydride group.

[0034] The proportion of the thermosetting resin component in the thermosetting resin composition 12 may be 20% by mass or more, 30% by mass or more, or 40% by mass or more, and may be 100% by mass or less, or 80% by mass or less, relative to the mass of the thermosetting resin composition 12. If the proportion of the resin component in the thermosetting resin composition 12 in the prepreg 1 is large, i.e., if the proportion of the inorganic filler is small, the thermal expansion coefficient after curing tends to be large.

[0035] Examples of inorganic fillers include alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, ceramic, and carbon.

[0036] The content of the inorganic filler may be, for example, 40 to 300 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler.

[0037] The average particle size of the inorganic filler may be 10 μm or less or 5 μm or less, or may be 0.001 μm or more. The maximum particle size of the filler may be 30 μm or less or 20 μm or less, or may be 0.001 μm or more. The average particle size and maximum particle size of the inorganic filler may be the average value and maximum value of the maximum width in a two-dimensional image of the inorganic filler observed with a scanning electron microscope (SEM), for example.

[0038] The thermosetting resin composition may further contain other components as necessary. Examples of the other components include an adhesion aid, a silane coupling agent, a triazole compound, a tetrazole compound, an ion scavenger, an antioxidant, and an organic filler.

[0039] The content of the thermosetting resin composition 12 in the prepreg 1 may be 40 to 80 mass % based on the mass of the prepreg 1. If the content of the thermosetting resin composition 12 in the prepreg 1 is large, the thermal expansion coefficient after curing tends to increase.

[0040] The width of the prepreg 1 may be, for example, 200 to 1300 mm. The thickness of the prepreg 1 may be, for example, 15 to 300 μm. If the thickness of the prepreg 1 is less than 15 μm, the flatness of the substrate tends to decrease relatively due to unevenness caused by the inorganic fiber substrate 11. If the thickness of the prepreg 1 is large, the warpage of the substrate tends to increase.

[0041] The prepreg 1 can be obtained, for example, by a method including impregnating an inorganic fiber substrate 11 with a resin varnish containing a thermosetting resin composition 12 and a solvent, and removing the solvent from the resin varnish.

[0042] From the viewpoint of electrical conductivity, the metal foil 3 may contain copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements. The metal foil 3 may be a copper foil, an aluminum foil, or a copper foil. An insulating resin layer may be provided on the surface of the metal foil 3 facing the prepreg 1.

[0043] The insulating substrate 10 and the substrate material 100 including the insulating substrate 10 may be formed by heating and pressurizing the laminate 5 under heating conditions in which the amount of heat applied to the laminate 5 from one side (first surface S1) of the laminate 5 is different from the amount of heat applied to the laminate 5 from the other side (second surface S2) of the laminate 5. In this case, the heating conditions may be determined so that multiple sample substrates warp toward the first surface S1 when heated. Different amounts of heat may change the amount of thermosetting resin component remaining in the insulating resin layer 12A, which is a cured thermosetting resin composition. If there is a difference in the amount of resin component between the front and back of the substrate material, warping tends to occur on the side with less remaining thermosetting resin component. The distribution of the remaining amount of thermosetting resin component in the thickness direction of the insulating resin layer 12A can be detected, for example, by a method for identifying the type and proportion of constituent components from the position, height, and area of ​​the exothermic peak observed by differential scanning calorimetry (DSC) measurement, or a method for identifying the type and proportion of constituent components from infrared spectroscopy (IR) absorption spectrum analysis.

[0044] The heating conditions for forming the substrate material 100 may include increasing the temperature of the laminate 5 to a molding temperature at a predetermined temperature increase rate, and maintaining the temperature of the laminate 5 at the molding temperature. In this case, the molding temperature may be, for example, 100 to 300° C. or 150 to 250° C. The heating and pressurizing time at the molding temperature may be, for example, 0.1 to 5 hours.

[0045] Typically, pressure is continuously applied to the laminate 5 while the laminate 5 is being heated. The pressure applied to the laminate 5 may be, for example, 0.2 to 10 MPa.

[0046] The device for heating and pressurizing the laminate 5 can be a heat press device. The heat press device may be, for example, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, or an autoclave molding machine. When the device for heating and pressurizing the laminate 5 is a heat press device, a metal plate may be placed on the surface of the metal foil 3 opposite to the prepreg 1.

[0047] The wiring board for a semiconductor package can be obtained, for example, by a method including forming wiring by a subtractive method on the metal foil 3 of the substrate 20 obtained from the substrate material 100, or by a method including forming wiring by a semi-additive method after removing the metal foil 3 as needed. If necessary, a through hole penetrating the insulating substrate 10 may be formed, and a conductive via filling the through hole may be formed.

[0048] A build-up layer may be formed on the substrate 20 serving as a core material. In this case, wiring connected to the semiconductor chip may be formed on the build-up layer. The build-up layer may be formed by, for example, a subtractive method, a full-additive method, a semi-additive process (SAP), a modified semi-additive process (m-SAP), or a trench method.

[0049] The trench method involves forming a build-up material or a photosensitive insulating material layer having a pattern including grooves on a substrate 20 as a core material, and filling the grooves with a conductive material. The conductive material formed outside the grooves is removed by a method such as CMP or flycutting.

[0050] A semiconductor package is manufactured by mounting electronic components including a semiconductor chip at predetermined positions on a wiring board prepared using the substrate 20 .

[0051] FIG. 8 is a cross-sectional view showing an example of a semiconductor package including a substrate obtained from a substrate material as a core material. The semiconductor package 50 shown in FIG. 8 includes a wiring substrate 30, an electronic component 40 including a semiconductor chip mounted on the wiring substrate 30, and bumps 35 provided on the side of the wiring substrate 30 opposite the electronic component 40. The wiring substrate 30 includes a substrate 20 obtained from the substrate material and having a first surface S1 and a second surface S2, and build-up layers 25 including wiring provided on the first surface S1 and the second surface S2 of the substrate 20. The electronic component 40 is flip-chip connected to the wiring substrate 30 via connection terminals 41 on the first surface S1 side of the substrate 20. An underfill 42 may be filled between the electronic component 40 (semiconductor chip) and the wiring substrate 30. The orientation of the substrate 20 in the semiconductor package 50 can be selected to reduce warpage of the semiconductor package 50 after heating for reflow or other processes.

[0052] DESCRIPTION OF SYMBOLS 1...prepreg, 5...laminate, 11...inorganic fiber substrate, 12...thermosetting resin composition, 20...substrate (sample substrate), 21...first substrate, 22...second substrate, 30...wiring board, 40...electronic component (semiconductor chip), 50...semiconductor package, 110...label, S1...first surface, S2...second surface.

Claims

1. A method for manufacturing a semiconductor package, comprising: cutting out a plurality of substrates having the first surface and the second surface from a substrate material for a semiconductor package having the first surface and the second surface on the back side thereof; classifying the plurality of cut-out substrates into a first substrate that warps toward the first surface side when heated and a second substrate that warps toward the second surface side when heated; and mounting an electronic component including a semiconductor chip on the surface on the first surface side of the wiring substrate including the first substrate or on the surface on the second surface side of the wiring substrate including the second substrate.

2. A method for manufacturing a semiconductor package, comprising: cutting out a plurality of substrates having the first surface and the second surface from a substrate material for a semiconductor package having the first surface and the second surface on the back side thereof; classifying the plurality of cut-out substrates into a first substrate that warps toward the first surface side when heated and a second substrate that warps toward the second surface side when heated; and mounting an electronic component including a semiconductor chip on the surface on the second surface side of the wiring substrate including the first substrate or on the surface on the first surface side of the wiring substrate including the second substrate.

3. A substrate material for a semiconductor package having a first surface and a second surface on the back side thereof, wherein a plurality of sample substrates having the first surface and the second surface, which are rectangular with a length of 60 ± 1 mm and a width of 60 ± 1 mm, cut out from the substrate material for a semiconductor package warp toward the first surface side when heated.

4. The substrate material for a semiconductor package according to claim 3, wherein 90% or more of 10 or more of the sample substrates cut out from one piece of the substrate material for a semiconductor package warp toward the first surface side when heated.

5. The substrate material for a semiconductor package according to claim 3, wherein the plurality of sample substrates exhibit a warpage amount of at most 10 μm or more and 350 μm or less when heated to 260°C.

6. The substrate material for a semiconductor package according to claim 3, having a label indicating the position of the first surface or the second surface of the substrate material for a semiconductor package.

7. The substrate material for a semiconductor package according to claim 3, wherein the substrate material for a semiconductor package includes an insulating substrate formed by heating and pressurizing a laminate including an inorganic fiber base material and a plurality of prepregs impregnated with a thermosetting resin composition in the inorganic fiber base material.

8. The substrate material for a semiconductor package according to claim 7, wherein the laminate includes a combination of two or more of the prepregs including the inorganic fiber substrates different from each other, and the two or more prepregs are laminated in an order selected so as to warp toward the first surface side when a plurality of the sample substrates are heated.

9. The substrate material for a semiconductor package according to claim 7, wherein the laminate includes a combination of two or more of the prepregs including the thermosetting resin compositions different from each other, and the two or more prepregs are laminated in an order selected so as to warp toward the first surface side when a plurality of the sample substrates are heated.

10. The insulating substrate is formed by heating and pressing the laminate under heating conditions in which the amount of heat applied to the laminate from one surface side of the laminate is different from the amount of heat applied to the laminate from the other surface side of the laminate, and the heating conditions are determined so as to warp toward the first surface side when a plurality of the sample substrates are heated. The substrate material for a semiconductor package according to claim 7.

11. A container including the substrate material for a semiconductor package according to claim 3, and a container that houses the substrate material for a semiconductor package and has a label indicating the position of the first surface or the second surface of the substrate material for a semiconductor package.

12. A method for manufacturing the substrate material for a semiconductor package according to claim 7, including forming an insulating substrate by heating and pressing a laminate including a plurality of prepregs including an inorganic fiber substrate and a thermosetting resin composition impregnated in the inorganic fiber substrate.

13. The method according to claim 12, wherein the laminate includes a combination of two or more of the prepregs including the inorganic fiber substrates different from each other, and the two or more prepregs are laminated in an order selected so as to warp toward the first surface side when a plurality of the sample substrates are heated.

14. The method according to claim 12, wherein the laminate includes a combination of two or more of the prepregs including the thermosetting resin compositions different from each other, and the two or more prepregs are laminated in an order selected so as to warp toward the first surface side when a plurality of the sample substrates are heated.

15. The method according to claim 12, wherein the insulating substrate is formed by heating and pressing the laminate under heating conditions in which the amount of heat applied to the laminate from one surface side of the laminate is different from the amount of heat applied to the laminate from the other surface side of the laminate, and the heating conditions are conditions determined such that when a plurality of the sample substrates are heated, they warp toward the first surface side.

Images